Seven seconds remained in the countdown to launch a conventional
hypersonic glide vehicle from the Kauai Test Facility (KTF) in Hawaii,
when a technical issue stopped the count. The Sandia launch team
scrambled to find the offending software script error and craft a
solution to keep the first test flight of the US Army’s Advanced
Hypersonic Weapon (AHW) on track.

“It was very nerve-wracking,” says David Keese, director of
Integrated Military Systems Development Center 5400, who was at KTF’s
Launch Operations Building to view the flight in the early morning hours
of Nov. 17. “We had to hold the countdown, examine what the problem
was, define a solution to the problem, coordinate the solution with the
flight test director, and implement that solution, which we did in
about 30 minutes.”

Problem solved, the countdown resumed, and the US Army Space and
Missile Defense Command/Army Forces Strategic Command (USASMDC/ARSTRAT)
AHW flew a non-ballistic glide trajectory at hypersonic speed in its
successful first test flight.

The three-stage booster system and glide vehicle were developed by
Sandia under the direction of the USASMDC/ARSTRAT. Thermal protection
system development for the glide body was the responsibility of the US
Army Aviation and Missile Research Development and Engineering Center
in Huntsville, Ala. The test flight was launched from Sandia’s Kauai
Test Facility.

The AHW program is part of DoD’s Conventional Prompt Global Strike
effort to develop conventional weapon systems that can deliver a
precision strike anywhere in the world within an hour. Success would
mean the US would have an alternative to nuclear weapons to prevent a
crisis and it would decrease the conventional military response time
significantly, David says.

The test flight represented about four years of work for up to 200
Sandia employees across the Labs. It came from a foundation of work on
projects from as long as 25 years ago, David says, including the Sandia
Winged Energetic Reentry Vehicle Experiment (SWERVE), the Strategic
Target System (STARS), and the Tactical Missile System-Penetrator
(TACMS-P).

A flight of many firsts

About 50 Sandia employees, including Defense Systems &
Assessments Div. 5000 VP Jeff Isaacson, viewed the test in Kauai. Eric
Schindwolf, deputy director of Strike and Aerospace Systems 5420, says
large screens projected digital animation driven by the actual data
coming from the AHW in real-time along with displays of the vehicle’s
condition as it reached certain milestones.

The historic flight had many firsts, David says. It was the first
time a Sandia-developed booster had flown a low-altitude, long-range
horizontal flight path at the edge of the Earth’s atmosphere; the first
time eight grid fins (designed by Sandia and Huntsville, Ala.-based
Dynetics Corp.) were used to stabilize a US missile system; and the
first time a glide vehicle flew at hypersonic speeds at such altitude
and range. This flight test incorporated lessons and data from previous
DARPA flight tests conducted as part of the Defense Department’s
Prompt Global Strike Program.

“You could almost feel the tension change to jubilation as the
launch occurred and the booster performed well and the grid fins
deployed,” David says. “At each milestone along the way, Sandia
employees were becoming more excited about the success because you
could see how the missile was flying. . . . Cheers would go up every
time we would meet one more mission milestone.”
The flight path took the vehicle up hundreds of thousands of feet and
then it flew toward the Earth’s surface before pulling up slightly to
fly horizontally within the atmosphere to the target, Eric says.

“We always knew the pull-up would be the most difficult part of
this. We knew that success was going to be historic,” Eric says. “So as
we watched this actually happen, the anticipation was really high.
Once we saw the vehicle was climbing and leveled out at its glide
altitude, we knew we had gotten through the hardest part. You could
feel the relief as the team immediately sensed that the rest of the way
would be comparatively easier.”

The success was praised by Sandia’s leaders, who flooded employee inboxes with congratulatory emails the next day.

Jeff called the flight a “stunning success” and a “real engineering achievement.”

At a team celebration after the mission, Jeff told the attendees,
“This success could not have been achieved without exceptional
teamwork, which was evident to anyone in the Launch Operations Building
that night.”

Sandia President and Labs Director Paul Hommert, who says he
couldn’t have been more proud to be a Sandian as he listened to the
test from Washington, D.C., wrote: “Once again today our Laboratory
rendered exceptional service in the national interest. For your
dedication, excellence, and professionalism thank you and
congratulations!"

Eric shared the general scope of Sandia’s work on the AHW. The
technical challenges that faced Sandia were aerodynamic stability,
aerodynamic heating, and control of the missile and glide vehicle, he
says.

Typically, boosters fly missiles to heights of millions of feet
above Earth, but the AHW flew only to a peak of hundreds of thousands
of feet above the Earth’s surface, before descending to a lower
altitude for the remainder of the flight. The modified STARS booster,
which was about 40 feet long and 54 inches in diameter, powered
maneuvers that had never been done before, Eric says.

The lower a missile flies in the atmosphere, the more it tends to
tumble end over end, he says, so Sandia helped develop the eight grid
fins to improve stability, which had never been used before on a US
missile.

Eric says Sandia’s researchers did not want to risk having the fins
interact with the missile exhaust near the ground, so four opened right
after clearing the launch tower and four more deployed when the first
stage burned out nearly 60 seconds later.

“They provided the margins of aerostability and control needed to prevent the missile from tumbling,” Eric says.

‘String of pearls’

Because the 2,485-mile (4,000-kilometer) flight from Kauai to the
Army’s Reagan Test Site on the Kwajalein Atoll was so low, the
curvature of the Earth prevented continuous monitoring from the takeoff
and landing sites alone, he says.

Space, air, sea, and ground platforms collected vehicle performance
data during all phases of the flight, according to a Pentagon news
release. The Sandia booster and glide vehicle transmitted data to this
network, called the “string of pearls,” Eric says.

Sandia also led the design and development of the glide vehicle,
including improved navigation, guidance, and control technologies and
teaming with AMRDEC to use advanced thermal protection materials to
protect it on the long flight in the atmosphere.

Sandia researchers also successfully designed and tested the Flight
Termination System for the AHW. This system protects public safety by
destroying the vehicle if it should fly off-course during a test
flight, he says.

The test’s objective was to collect data on the technologies and
test range performance for long-range atmospheric flight. The mission
emphasized aerodynamics; navigation, guidance, and control; and
thermal-protection technologies, according to the Pentagon news
release.

Eric says Sandia employees are analyzing the data from the test
flight, which will be used by DoD to model and develop future
hypersonic boost-glide capabilities.

“This was only a very first demonstration,” Eric says. “This is not
a weapon by any stretch of the imagination. There’s quite a bit of
work that needs to be done.”

David says the information gathered also will be used to validate
Sandia’s computational models so they can be used with more confidence
in the future.

David had nothing but praise for the people who spent nights, weekends, and many long hours working at KTF and the Labs.

“All the credit for the success of this effort goes to the team and
its tremendous commitment and dedication that produced these
extraordinary accomplishments that enhance our country’s national
security,” he says.
--Heather Clark

Sandia filed a patent last September for a unique materials approach
in multilayered, ceramic-based, 3-D microelectronics circuits, such as
those used in cell phones. The approach compensates for the effects of
how something called the temperature coefficient of resonant
frequency, which is one critical property of materials aimed at radio
and microwave frequency applications, changes due to temperature
fluctuations. The work was the subject of a two-year Early Career
Laboratory Directed Research and Development (LDRD) project that wrapped
up in March.

The LDRD team focused on developing fundamental understanding of why
certain materials behave as they do. That knowledge could help
manufacturers design and build better products.

Steve, who spent 14 years with Motorola before joining the Labs in
2009, says Sandia was interested in the research for its own programs,
but the work also has potential commercial applications. He says,
however, no exact projects have been pinpointed.

“At this point we’re just demonstrating the technology,” he says.
“We have to demonstrate that it’s practical, that we can design a
device with it, that we can design it over and over again, and can
design it reliably.”

Wasting potential bandwidth

The familiar cell phone illustrates how the development might be used.

The Federal Communications Commission allocates bandwidth to various
uses — aviation, the military, cell phones, and so on. Each must
operate within an assigned bandwidth which, like a pipeline, has finite
capacity. But temperature variations in operating a cell phone cause
the properties of the materials inside to change, and that causes a
shift in resonant frequency at which a signal is sent or received.

Because of that shift, cell phones tend to operate in the middle of
the bandwidth, avoiding the edges so as not to break the law by
drifting outside the assigned frequency range. That necessary caution
wastes potential bandwidth and sacrifices the rate at which data can
move.

Under the LDRD, Steve worked on low temperature co-fired ceramic
(LTCC), a multilayer 3-D packaging and interconnection technology that
can integrate passive components. Most mainstream LTCC dielectrics now
on the market have a temperature coefficient of resonant frequency in a
range as wide as that between northern Alaska in the winter and
southern Arizona in the summer. A dielectric is a material, such as
glass, that does not conduct electricity but can sustain an electric
field.

Steve’s research achieved a near-zero temperature coefficient by
incorporating compensating materials into the multilayer LTCC
structure.

A graph shows the differences. Resonant frequencies used in various
LTCC base dielectrics today appear as slanted lines on the graph as
temperatures change. Steve’s approach to an LTCC leaves the line
essentially flat — indicating radio and microwave resonator frequency
functions that remain stable as temperatures change.

“The critical kind of understanding about the science here is
required to design the material right to achieve properties that
complement each other,” Steve says.

He presented the results of the approach in a paper published in
January in the Journal of Microelectronics and Electronic Packaging.

“We can actually make adjustments in the materials property to make sure the resonance frequency doesn’t drift,” Steve says.

And, he says, “if your materials property doesn’t drift with the
temperature, you can fully utilize whatever the bandwidth is.”

Another advantage: Manufacturers could eliminate additional
mechanical and electrical circuits now built into a device to
compensate for temperature variations, he says. That would reduce
costs.

One basic challenge of the project was choosing different materials
that don’t fall apart when co-fired together, Steve says. Glass ceramic
materials used are both fragile and rigid, but they’re also very solid
with minimal porosity. Researchers experimented with different
materials, changing a parameter, adjusting the composition, and seeing
what worked compatibly.

“It’s in a sense like cooking, you mix all these things together —
it’s cooking. You have these ingredients, certain things you do in
certain ways, just making sure it works together. Even the equipment is
very similar; we have furnaces, ovens, mixers. . . . Each step is very
much like making bread or something,” he says.

Steve had to consider both physical and chemical compatibility.
Physical compatibility means that as materials shrink when they’re
fired, they shrink in the same way so they don’t warp or buckle.
Chemical compatibility means each material retains its unique
properties rather than diffusing into the whole.

Looked at variables to boost performance

The LDRD created a new set of materials to solve the problem of
resonant frequency drift but also developed “more of an understanding
of why this works this way,” Steve says. “Why select material A and not
B, what’s the rationale? Once you have A in place, what’s the behavior
when you make a formulation change, a composition change, do little
things?”

Researchers looked at variables to boost performance. For example,
the functional material within the composite carries the electrical
signal, and researchers experimented with placing that material in
different areas within the composite until they came up with what
worked best and understood why.

“That’s really important, the why,” Steve says.

The team also constructed a computational model to analyze what
happens when materials with different properties are placed together,
and what happens if you change their order in the stacked layers or the
dimensions of one material versus another.

“We study all these different facets, the placement of materials,
the thickness, to try to hit the sweet spot of the commercial process,”
he says. That’s where computer modeling helps.
“Modeling can calculate all these things,” Steve says. “Modeling’s
important. You cannot do exhaustive experiments. Modeling can change
whatever you want, once you have the basic experiment.”

Manufacturing can be done as a simple screen printing process, a
low-cost, standard commercial process much like printing an image on a
T-shirt. Steve says the idea was to avoid special requirements that
would make the process more expensive or difficult.

“That’s kind of the approach you try to take, make it simple to use
with solid understanding of the fundamentals of materials science,” he
says.
--Sue Major Holmes

A former DARPA robot developed at Sandia is now serving an educational purpose at New Mexico Highlands University (NMHU).

About a decade ago, Sandia developed the Multi-function Utility
Logistics Equipment Vehicle, or MULE, robot. The project was sponsored
by DARPA — the Defense Advanced Research Projects Agency — Lockheed
Martin, and Sandia to help troops haul heavy equipment across a variety
of terrains, and could negotiate one-meter steps. But once the MULE
had served its purpose, it was parked in a garage at Sandia’s Robotic
Vehicle Range and left alone until the summers.

For the past two summers, students and Gil Gallegos, chair of the
computer and mathematical sciences department at Highlands, worked with
the MULE as part of DOE’s FAST, or faculty/student program, which pairs
students with professors for research projects.

Gallegos and NMHU students added hardware and software to expand the MULE’s capabilities.

“Every summer, we’d dust this off, and students would get very
excited to work on it for the summer,” says Jake Deuel (6532), manager
of the Robotic and Security Systems group. “We realized we weren’t
doing anything with it, and found a way to donate it to NMHU for two
years.”

Gallegos says the goal of having the MULE at the university’s lab is
to help generate thesis topics for graduate students in the computer
science department and for undergraduate senior capstone projects. He
adds that it will be a valuable recruiting tool to encourage students to
pursue STEM careers.

“We’re very appreciative of Sandia allowing us to use this. It
really does improve our program, and it’s very exciting to have the
robot in the lab and to have students excited about it,” Gallegos says.

Miguel Maestas earned his bachelor’s degree in computational
engineering from NMHU two years ago and is now in his second semester as
a master’s student. He says the MULE will be instrumental to his
thesis work, and is anxious to start working with it. He will first run
diagnostics to ensure all electronic parts are intact, and has plans
to integrate a 3-D image capture function. Eventually, this would help
with object and possibly facial recognition to enhance the robot’s
navigational capabilities.

Currently, four undergraduate and three graduate students are signed
up to work with the MULE, but Gallegos expects that having the robot
on campus will continue to generate interest. Other projects in the
works include software development to communicate with motors that
control the MULE’s six wheels and shoulders and installing
microcontrollers for individual joints, shoulders, and wheels.

“I’m hopeful that this will help recruit other students into the
computer sciences department. It’s very exciting to be able to work with
the MULE and to know that it has been used to help develop other
projects that are state-of-the-art,” Maestas says.
--Sue Major Holmes

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.